title: The reflexion coefficient as a measure of transepithelial permeability in the isolated rabbit pancreas.
abstract: 1. The reflexion coefficients of a number of non-electrolytes and electrolytes have been determined in the isolated rabbit pancreas. 2. The reflexion coefficients of the following non-electrolytes were: urea, -0.02; glycerol, 0.06; erythritol, 0.11; sorbitol, 0.41; mannitol, 0.42; arabinose, 0.72; xylose, 0.74, assuming a value of 1.00 for sucrose. 3. These values are equal within the experimental error to values previously obtained with a tracer technique for the same preparation, but they are significantly lower than those reported by other investigators for the isolated perfused cat pancreas. 4. Addition of 100 mM-sucrose to the bathing medium resulted in proportionally increased Na+ and K+ concentrations in the secreted fluid. The secreted fluid remained isotonic with the bathing medium under all circumstances. 5. Addition of 10(-5) M-carbachol to the bathing medium led to a reduction in the reflexion coefficient of sucrose from 1 to 0.85, but only when 25 mM-sucrose was used. 6. The reflexion coefficients of electrolytes were: NaCl, 0.50; KCl, 0.51; NaHCO3, 0.52 and choline chloride, 1.02. 7. It is concluded that the isolated rabbit pancreas is highly permeable, both to electrolytes and to small non-electrolytes, probably being more leaky than any other epithelium studied so far.
mesh_terms: D000818:Animals; D001089:Arabinose / Q000378:metabolism; D002217:Carbachol / Q000494:pharmacology; D002463:Cell Membrane Permeability; D004573:Electrolytes / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D008353:Mannitol / Q000378:metabolism; D010179:Pancreas / Q000378:metabolism*; D010189:Pancreatic Juice / Q000378:metabolism; D011817:Rabbits; D012636:Secretory Rate / Q000187:drug effects; D013395:Sucrose / Q000378:metabolism / Q000494:pharmacology; D014508:Urea / Q000378:metabolism
chemical_list: D004573:Electrolytes; D008353:Mannitol; D013395:Sucrose; D014508:Urea; D002217:Carbachol; D001089:Arabinose